Gray's Grasshopper Warbler Helopsaltes fasciolatus Scientific name definitions

16·5–18 cm; 24–31 g. A large Helopsaltes, strong-billed with longish graduated tail and pointed feather tips, and unstreaked plumage. Adult is warm olive-brown above , more tawny on rump, tinged greyer on top of head; sides of head olive-brown, darker lores and distinct whitish supercilium, cheek mottled grey-buff; upperwing-coverts, tertials and edges of flight-feathers warm olive-brown, uniform with mantle, tail dark tawny-brown; whitish below, washed grey-brown across breast, throat and upper breast usually with dusky mottling; flanks olive-brown, undertail-coverts cinnamon-buff; iris dark brown or mid-brown; bill dark brown or blackish above, greyish flesh or pale grey-brown with darker tip below; legs flesh-pink or flesh-yellow to pale brown. In worn plumage, upperparts are duller brown or olive-brown, with warm coloration confined to rump/uppertail-coverts, greyish-white supercilium providing better contrast with head-sides and crown, pale greyish-white chin, dull ash-grey underparts, diffusely barred on upper breast, and paler, creamy-buff undertail-coverts. Sexes alike. Juvenile is darker above than adult, upperparts often distinctly russet, supercilium, cheek and underparts washed olive-yellow, more prominent dark brown spotting from chin to breast.

Until recently treated as conspecific with H. amnicola (which see). Monotypic.

SC Siberia (from E of upper R Ob) E to SE Russia (Amurland, Ussuriland) and NE China (NE Inner Mongolia, N Heilongjiang); non-breeding S Philippines, Sulawesi, Moluccas and W New Guinea.

Breeds in river-valley meadows, edges of taiga, forest glades and clearings, and bamboo thickets; favours tall rank herbage, grassy thickets, tangles of nettles (Urtica) and shrubbery, and secondary regrowth; mainly in lowland and coastal areas. Mainly in thickets, forest edge and tall grass in non-breeding areas; to 1000 m in Wallacea (Sulawesi) and 1800 m in New Guinea.

Long-distance migrant. Leaves breeding areas late Aug/early Sept; C Siberian breeders move E to join E populations heading into NE China and along E China coast, but there are, surprisingly, no records from Japan. Arrives in non-breeding areas in Wallacea from Sept and New Guinea from early Oct (where remains until at least Apr), but passage through Philippines starts as early as late Aug, with records as late as Dec. Spring return migration begins early May, mostly following autumn routes but in reverse direction, and with peak passage across the Philippines in May (until last week), and China in late May and early Jun, although the species is very rare in E China and Taiwan at this season; reaches E breeding grounds from end of May, C Siberia from mid-Jun, where passage may continue as late as fourth week of Jun. Rare winter records in E New Guinea (but regular in Dec–Jan in Fly R region), New Britain (Dec) and New Ireland (Apr). Three sight records from N Australia (1979, 1981 and 2001) not accepted, but one was photographed in Western Australia in Oct 2013. Vagrant in W Europe, in France (Sept 1913) and Denmark (Sept 1955). A third record, also from W France, a specimen claimed to have been collected in Sept 1933, is now believed to be bogus.

Insects. Forages among grass stems or deep within bushes.

Song  (individually variable) of rich fluty, mellow and musical notes, a loud (far-carrying), explosive and bulbul-like “tryt-to tryt-to trytorytoryt” with rapid terminal section, lasting c. 2–3 seconds in all, at 1–5 kHz, repeated continuously at intervals of c. 2 seconds for up to 20 minutes; contact call  a trilling “cherr-cherr…”, a distinct “tek-tek”, or “terreck-terreck, terreck terreck-terreck...” and a sharp “chuck”. Rarely calls in autumn on passage, but spring migrants are very vocal. Song often heard in winter, but during breeding season is mostly heard at dawn and dusk.

Breeds mid-Jun to early Jul. Territorial. Nest a large, deep cup of dead leaves and dry grass stems, lined with finer stems, placed on moist soil covered by leaves and twigs, among nettles, by grass clump or under small bush. Clutch 3–4 eggs; incubation period c. 15 days; nestling period c. 14 days.

Not globally threatened (Least Concern). Common to fairly common throughout most of its wide range in C & E Palearctic. Locally common in Siberia; rather uncommon in China. Reports of breeding in North Korea unconfirmed and there are apparently just five records from there. Generally widespread and common in non-breeding range, with records from many islands in the Moluccas (e.g. Sulu, Buru, Ambon, Seram, Obi, Bacan, Halmahera, Ternate and Morotai), suggesting healthy population. Forest clearance within Indonesia and New Guinea may have improved conditions for this species within its winter range.